JPH0454677Y2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Application Field] This invention relates to a picture tube (hereinafter referred to as CRT) used, for example, in television receivers or computer terminals.

[Conventional technology]

FIG. 6 is a partially cutaway side view showing the structure of a conventionally used shadow mask type color CRT.
, a funnel-shaped funnel 4 connected to the panel side surface 2b, and a net 5 that includes an electron gun (not shown).
It is a vacuum glass container consisting of. A fluorescent screen 3 is provided on the inner surface of the panel screen portion 2a, and a shadow mask 6 with numerous holes is arranged opposite to it. The fluorescent screen 3 needs to be composed of a plurality of phosphors, and the shadow mask 6 needs to be attached and detached from the panel 2 multiple times, so the panel 2 and funnel 4 are designed to be separable. This panel 2
and the funnel 4 are sealed with fritted glass, which is glass solder, and this part is the sealed part 7.
It is. Such as glass vacuum container
With CRTs, there is a possibility that scratches on the glass may expand and lead to a type of destruction known as implosion. To prevent this, a paper tape 8 is usually wrapped around the panel side surface 2b, and a metal band 10 is wound and tightened over the tape to prevent the cracks generated on the panel screen portion 2a side from extending toward the sealing portion 7 side. Perform explosion-proof treatment that serves the purpose of In addition, the metal band 10 is attached to the mounting bracket 9 for attaching the CRT 1 to the receiver.
It is clamped and fixed at the same time when it is wound.

As shown in FIG. 7, the rectangular fluorescent screen 3 has a long axis X, a short axis Y, and a diagonal axis P, and its tube axis Z coincides with the center of the screen 3. By the way, in a conventionally designed CRT,
As shown in FIG. 8, the panel screen portion 2a is deformed by the vacuum so as to draw a contour line M having substantially the same shape as the rectangular screen 3. This means that the principal stress at the side center portion 11 of the panel screen portion 2a in the direction along the X and Y axes is larger than that at the corner portion 12 of the screen 3 in the P-axis direction. The shaded area 20 indicates the area where the principal stress is large. Figure 9 shows only the first quadrant corresponding to 1/4 of the CRT1, including the panel center, and the line along the tube wall of the CRT1 in the Y-axis section is SA, and similarly, the X-axis section and the P-axis The cross sections are defined as LA and DA, respectively. In the figure, the end portion of the panel screen portion 2a, the edge portion 2c, the panel side portion 2b, the vicinity of the sealing portion 7, etc.
This is a problem in terms of the strength of the CRT.

By the way, in order to evaluate the degree of safety of CRT, we purposely scratched the panel screen part 2a side and investigated the occurrence of cracks, the extension of cracks, and
When examining the state of implosion, two locations where principal stress is high, the end of the panel screen portion 2a and the sealing portion 7, are particularly problematic in terms of strength. The following explanation is a discussion about the strength of the sealing part 7, and this is discussed in RCA Review vol39.Dec.1978 by RCA, USA.
has been reported in detail. FIG. 10 is an enlarged sectional view of the vicinity of the sealing part in the conventional CRT described in the above report, in which both the sealing surfaces 13 and 14 of the panel side part 2b and the funnel 4 are made of frit glass (not shown). ) shows the sealed state. Here, W is the overlapping width of the panel side part 2b and the funnel 4, PW is the width of the sealing surface 13 of the panel side part 2b, and FW is the sealing surface 1 of the funnel 4.
4, PD and FD respectively indicate the width from the screen center to the thickness center position of the sealing surfaces 13 and 14. If it becomes narrower, the strength against vacuum in the sealing portion 7 will deteriorate.

Therefore, conventionally, as shown in Figure 11, PD≒
By setting FD, FW≒PW+1.72mm,
When the panel side part 2b and the funnel 4 are misaligned, deterioration in strength against vacuum is prevented without significantly reducing the overlap width W.

Further, as shown in FIG. 12, another conventional example is as follows.
PD≒FD, PW≒FW, and further, the outside flesh of the funnel 4 is shaved from the sealing part 7 side of the funnel 4 to the neck 5 side over the entire circumference, thereby, I'm trying to reduce the weight of the CRT.

[Problem that the invention attempts to solve]

However, in the above-mentioned conventional CRT, since the funnel 4 shown in FIG. 11 protrudes further outward than the panel side surface 2b, it is easily damaged during manufacturing and transportation, resulting in a lower explosion-proof performance level. This negates the advantage of measures to prevent the overlap width W from narrowing. Similarly, the 12th
There has been a problem in that the step portion 21 provided on the neck 5 side of the funnel 4 shown in the figure is more likely to be damaged during manufacture and transportation.

Furthermore, in each of the above-mentioned conventional examples, it is difficult to set PD≒FD due to the process, and as a result, there is a problem that the strength of the sealing portion 7 is inevitably deteriorated due to misalignment between the panel 2 and the funnel 4. . In other words, the sealing portion 7 between the panel 2 and the funnel 4 is the main cause of variations in the strength of the CRT due to unavoidable variations that occur during the manufacturing of the panel 2 and the funnel 4.

This invention was made in order to solve the above-mentioned conventional problems, and aims to increase the strength of the sealed portion against vacuum, thereby providing a picture tube with an improved level of explosion-proof performance.

[Means for solving problems]

In the picture tube according to this invention, the width of the mutually opposing sealing surfaces of the panel and the funnel at the center of the side of the panel is set to be larger than the width of the mutually opposing sealing surfaces of the panel and funnel at the corner portions. It has a wide range of settings.

[Effect]

According to this invention, the width of the sealing surface is set wider at the center of the side than at the corner, so that the sealing surface of both the side surface of the panel and the funnel can be prevented due to misalignment between the panel and the funnel. This prevents the overlap width from becoming significantly narrower near the center of the side, as in the conventional case. This ensures sufficient sealing performance between the two sealing surfaces at the central portion of the side where the principal stress is high, and increases the strength against vacuum near the sealing surfaces.

[Example of idea]

Embodiments of this invention will be described below with reference to the drawings.

FIG. 1 is an exploded perspective view showing an embodiment of this invention. In the figure, 13 is the sealing surface of the panel side surface 2b, and the X-axis (long axis) of the fluorescent screen 3 in FIG. Center part 12 of the side along the Y-axis (minor axis) direction
Nearby inner surfaces 12a each protrude inward in the X-axis and Y-axis directions in a semicircular arc shape. The width (thickness) of the sealing surface 13 at the center portion 12 of the side along the X-axis direction is PLW, and the center portion 12 of the side along the Y-axis direction is PLW.
The width of the sealing surface 13 in PSW, P axis (diagonal axis)
When the width of the sealing surface 13 at the corner portion 11 along the direction is PDW, the relationship PSW>PLW>PDW holds true. In other words, conventionally, PSW=
Whereas PLW=PDW≒7mm, in this example, for example, PSW=12.0mm, PLW=9.0
mm and PDW=7.0mm, respectively.
The difference between PSW and PLW with respect to PDW is set depending on the height of the principal stress applied to the center portion 12 of the side (see FIG. 8).

On the other hand, the sealing surface 14 of the funnel 4 in FIG.
Formed in plane symmetry with the sealing surface 13 of the panel 2,
It has the same shape and dimensions (width) as the sealing surface 13. In addition, the widths FDx, FDy, from the Z axis (tube axis) of the funnel 4 to the thickness center position of the sealing surface 14,
FDp is each width from the panel center O of the panel 2 to the thickness center position of the sealing surface 13 shown in FIG.
PDx, PDy, PDp are set equal to each other,
This allows the two sealing surfaces 13 and 14 to come into surface contact while facing each other.

In the above configuration, the first
A panel 2 and a funnel 4 having sealing surfaces 13 and 14 having the same shape and dimensions as shown in the figure are separately formed,
Panel 2 and funnel 4 are completed as CRT parts through a phosphor coating process, a shadow mask installation process, etc. Next, as shown in FIG. 3, with the panel center of the panel 2 and the Z axis of the funnel 4 aligned, the sealing surfaces 13 and 14 are butted against each other, and both sealing surfaces 1 are aligned with a fritted glass.
Seal 3 and 14. Here, the width PSW at the center part 12 of the side of the sealing surfaces 13 and 14 shown in FIG.
(=12.0mm) and PLW (=9.0mm) are set wider (thicker) than the conventional width (PSW=PLW=7.0mm), so if the width shown by the solid line in Figure 4 is Even if the other sealing surface 14 is misaligned with respect to the sealing surface 13 of the side as shown in the imaginary line, that is, the panel center O and the Z axis are misaligned, even if the side center portion 12 This prevents the overlapping width W of both sealing surfaces 13 and 14 from becoming extremely narrow as in the conventional case. Therefore, when sealing, panel 2
Even if the positioning accuracy between the funnel 4 and the funnel 4 is somewhat poor, sufficient sealing strength of the sealing surfaces 13 and 14 at the side center portion 12 can be obtained.

In addition, when an electron gun is included in the net 5 in FIG. 1 after the above sealing process and the inside of the CRT is then evacuated, the vicinity of the sealing surfaces 13 and 14 at the center part 12 of the side where the principal stress is high becomes thick. Because I'm getting used to it,
The strength against vacuum at the side center portion 12 is increased, and variations in stress distribution between the corner portion 11 and the side center portion 12 in the sealing portion 7 as shown in FIG. 9 can be eliminated. Therefore, the panel screen portion 2a
The extension of the crack from the side to the funnel 4 side is suppressed, and the implosion resistance level of the CRT can be improved.

Furthermore, depending on the height of the principal stress applied to the side center portion 12, the width PLW of the sealing surface 13 in FIG. Since the widths are set to be the same, the weight increase of the entire CRT can be kept low.

Note that, after the CRT is evacuated, explosion-proof treatment is performed using the metal band 10 as in the conventional case.

The widths PSW and PLW in FIG. 2 are not limited to the values in the above embodiment. However, PDW
If PSW and PLW are significantly different from each other, a problem arises in that it is difficult to manufacture the panel 2. Therefore, it is preferable to set the widths PSW and PLW to at least 0.5 mm or less less than PDW.

As another embodiment of this invention, as shown in FIG. 5, the inner surface of the sealing surface 13 at the center part 12 of the side is made flat, and the outer surface is built up.
PLW, PSW may be set, and PLW,
The PSW may be distributed to both the inner surface and the outer surface.

As yet another embodiment of this invention, the sealing surfaces 13 and 14 of the panel 2 and funnel 4 shown in FIG.
The shape and dimensions (width) of the sealing surface 14 of the funnel 4 are varied along the X-axis, Y-axis, and P-axis.
When FSW, FLW, and FDW are used, PSW in Figure 2,
In relation to PLW and PDW, PSW<FSW,
PLW<FLW, PDW<FDW, and then PDx>
It is also possible to set FDx, PDy>FDy, PDp>FDp.

[Effect of idea]

As explained above, according to this invention, the strength against vacuum is increased near the sealing surface at the center of the side of the panel, thereby suppressing cracks that occur on the screen side of the panel from extending toward the funnel side. be done. This makes it possible to improve the implosion resistance level of the CRT.

[Brief explanation of the drawing]

FIG. 1 is an exploded perspective view showing an embodiment of this invention, FIG. 2 is a front view showing the sealing surface, and FIG. 3 is a partially cutaway side view showing the panel and funnel after being sealed.
Fig. 4 is a partial front view showing the misalignment of both sealing surfaces, Fig. 5 is a front view showing another embodiment of this invention, and Fig. 6 is a partially broken view illustrating the structure of a conventional CRT. Figure 7 is a front view of Figure 6, Figure 8 is a contour diagram showing the deformation of the panel due to vacuum, Figure 9 is a stress distribution diagram explaining where the principal stress of the CRT is high due to vacuum, Figure 10 is a side view. Figures 1 to 12 are enlarged cross-sectional views for explaining the shapes and dimensional relationships of conventional panels and funnels. DESCRIPTION OF SYMBOLS 1... Picture tube, 2... Panel, 2a... Panel screen part, 2b... Panel side view, 3... Screen, 4... Funnel, 5... Network, 1
1...Corner part, 12...Side center part, 13, 14
...Sealing surface, X...Long axis, Y...Short axis, P...Diagonal axis, PSW, PLW, PDW...Width of sealing surface. Note that the same reference numerals in the figures indicate the same or corresponding parts.

Claims (1)

[Claims for Utility Model Registration] (1) A picture tube with a vacuum-sealed structure consisting of a panel having a rectangular screen, a funnel sealed to the side surface of the panel, and a neck connected to the funnel; The width of the mutually opposing sealing surfaces of the panel and funnel near the center of the side is set wider than the width of the mutually opposing sealing surfaces of the panel and funnel at the corner portions. Picture tube. (2) A utility model in which the width of the sealing surface at the center of the side along the long axis direction of the square screen is set narrower than the width of the sealing surface at the center of the side along the short axis direction. A picture tube according to registered claim 1.